Pulp beating machine



April 24, 1934. M, MlLLS PULP BEATING MACHINE Original Filed Jan. 27, 1951 2 Sheets-Sheet gvwe/wbwz MMills,

April 24, 1934. M. 5 1,955,758

PULP BEATING MACHINE o i i l Filed Jan. 27 1951 2 Sheets-Sheet 2 l 'ji gu Z7 Z6 25 I 714 A K; 215 70 W P 76 70 Patented Apr. 24, I934 PULL BEATING MACHINE Melvin A. Mills, Lawrence, Mass.

Application January 27,

1931, Serial No. 511,602

Renewed July 20, 1933 11 Claims.-

This invention relates to pulp beating engines of the so-called Holland type, wherein an endless channel is provided to receive the pulp,

and beater rolls are disposed across said channel at spaced points for successive operation on the pulp to maintain the same in circulation through said channel and to reduce the same to a uniform consistency.

In pulp beating engines of the so-called Holland type employing two or more beater rolls, it is usual to arrange the second roll at a higher elevation than the first roll, and the third roll, if a third roll is provided, at a higher elevation than the second roll, and so on if an additional roll or rolls is or are provided, and to provide so-called back-falls or dam elements between the rolls whereby clogging of the pulp mass and back-pressure against the-rolls is substantially eliminated. As the rolls revolve, each roll has a tendency to throw the pulp mass upwardly andtoward the next roll. Accordingly, it has been more or less common practice heretofore to pro-. vide a cover element above the rolls for the purpose of receiving the pulp thrown by one roll and directing or guiding it properly toward the next roll, thereby to further enhance the efiiciency of the engine. It has been found, however, that these cover elements, as heretofore constructed, are not entirely satisfactory, as some of the pulp tends to lodge at different places in said elements and, therefore, does not undergo a thorough beating. If these lodged masses of pulp remained lodged in the cover element, no serious disadvantages would result. The dilficulty is, however, that the lodged, unbeaten pulp masses may fall at any time into the more thoroughly beaten pulp mass which is being circulated through the engine, thereby impairing the quality of the mass as a whole and frequently requiring the beating operation to be continued over excessive periods of time.

Accordingly, the general object of the present invention is to provide a cover element for the purpose stated which is of such construction that 45 lodging of any portion of the pulp mass therein is substantially eliminated.

Another object of the invention is to provide a cover element for the purpose stated which is itself effective to produce a mixing of the pulp mass thrown thereagainst.

Another object of the invention resides in the provision of means whereby the outer portions of the pulp mass thrown by one roll are directed toward the center of the next roll, thereby to assure thorough beating of all portions of the pulp mass.

With the foregoing and other objects in view, which will become more fully apparent as the nature of the invention is better understood, the same consists in the novel features of construction, combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings and defined in the appended claims.

In the drawings, wherein like characters of reference denote corresponding parts in the different views:

Fig. 1 is a top plan view of 'a pulp beating engine embodying a cover element constructed in accordance with a practical embodiment of the invention;

Fig. 2 is a longitudinal section on the line 2-2 of Fig. 1;

Fig. 3 is a transverse section on the line 33 of Fig. 2; and

Fig. i is a transverse section on the line 44 of Fig. 2.

' Referring to the drawings in detail, 10 designates a pulp tub of elongated form within which is arranged a central, upstanding, longitudinally extending mid-feather or partition 11 which terminates short of the ends of the tub and thereby divides the latter into a single endless trough or channel 12 through which the pulp mass is adapted to be circulated.

In the present instance the tub 10 is equipped with two beater rolls which are designated as 13 and 14, respectively, and, as shown, these'rolls are mounted for rotation at suitably spaced points in the-channel 12, each for cooperation with a knife element 15 disposed therebeneath.

The direction of travel of the pulp mass through the channel 12 is indicated by the arrow 16 in Fig. 1 of the drawings and, therefore, according to the structure illustrated, the beater roll 13 is the first roll to act on the. pulp mass. This roll is suitably driven in the direction of the arrow 17 in Fig. 2 of the drawings with the result that the pulp mass is drawn beneath the roll and is initially comminuted by the cooperation of said roll with the related knife element 15. A dam wall 18 extends contiguous to the roll 13 at the rear side thereof and cooperates with said roll to provide a relatively narrow passage through which the initially comminuted stock is thrown upwardly by the roll.

The dam wall 18 terminates in a peak 19 disposed at any suitable elevation relative to the roll 13, preferably somewhat above the axis of the roll, and from this peak a bottom wall 20 extends downwardly toward the roll 14, which latter roll is disposed above the roll 13. Preferably the roll 14 is of smaller diameter than the roll 13 and is rotated at a faster rate of speed than said roll 13, whereby the pulp mass is removed rapidly from behind the roll 13 to avoid any back pressure of the pulp mass against said roll 13, this clearing of the pulp mass from behind the roll 13 being augmented by the downward slope of the bottom wall 20 from the peak 19 as is manifest.

Behind the roll 14 is a so-called back-fall or dam wall 22 which rises to a peak 23 at a suitable elevation with respect to said roll 14 and which slopes from said peak downwardly, as at 24, whereby clearing of the pulp mass from behind the roll 14 and back pressure of the pulp mass against said roll is avoided. As is understood, the initially comminuted pulp mass is again comrninuted as it passes beneath the roll 14 between said roll and the related knife element 15, said pulp mass after passing the roll 14 flowing to the lower portion of the tub 10 and returning to the roll 13 where beating thereof is again initiated.

Referring now to the present novel cover element against which the pulp mass thrown upwardly by the roll 13 is adapted to impinge and which is adapted to direct such pulp mass toward the roll 14, it will be observed that said cover element, which is designated generally as 25, includes a portion 25 overlying the roll 13, a'porti'on 27 overlying the roll 14, and a portion 23 overlying the space between said rolls and connecting the portions 26 and '27 together. The portion 26 meets the portion 28 in an arched edge 29 which extends transversely of the engine, i. e. in the direction of the axes of the rolls 13 and 14, at a suitable elevation above the peak 19, while the portion 27 meets the portion 28 in a straight edge 30 which extends horizontally in the direction of the axes of the rolls l3 and 14, and at a suitable elevation above the wall 20, the edges 29 and 30 being disposed, preferably, closely adjacent to the rolls 13 and 14, respectively.

Referring now to the sectional views, Figs. 3 and 4, it will be observed that the portion 28 of the cover element is transversely arched and is merged into the side walls 31, 31 of said cover element by rounded corners as indicated at 32, the side walls 31, 31 being either vertically straight as shown, or, if desired, being curved inwardly from the corners 32, whereby any pocket formations in which the pulp stock might lodge are totally avoided, and whereby the pulp stock that is thrown against the side and top walls is directed inwardly toward the center of the top wall. As a result there is a thorough mixing of the stock as the same travels between the rolls 13 and 1-4, the outside portions of the thrown stock being constantly directed toward the middle of the cover portion 28 and toward the middle of the roll 14. To assist in directing the outside portions of the thrown stock toward the middle of the roll 14, and to positively assure this mixing action of the stock, the side walls 31, 31 either are themselves converged inwardly adjacent to the roll 14, or are provided with plates 33, 33, respectively, which are disposed in converging relation toward the roll 14. This has the added advantage of restricting the so-called draft channel through which the pulp stock flows to the roll 14 with the desirable result of regulating the amount of stock maintained within the throat between the rolls and improving both the sud tion action of the roll 14 upon the stock and the mixing of the stock. And even in instances where the sides 31, 31, of the cover are curved inwardly towards the roll 14, plates such as those indicated at 33 in Fig. l of the drawings may be employed to further restrict the draft channel to adapt a single cover 25 for operation upon different grades of stock.

It will be noted that the cover portion 28 is arched not only transversely, but also longitudinally; that is, in a direction at right angles to the axes of the rolls 13, 14 between the edges 29, 30. This obviously permits free flow of the stock from the roll 13 and serves, in conjunction with the backfall between the rolls 13, 14, to avoid any clogging of the stock between said rolls. Furthermore, it will be apparent in this connection that due to the edge 30 being straight and merg ing gradually into the transversely and longitudinally arched cover portion 28, as shown, there will be an added mixing action of the stock just prior to the same being acted upon by the roll 14.

While only two beater rolls have been illustrated in the present instance, it will be understood that any desired plurality of beater rolls may be employed, and that said rolls may be of various different diameters and be arranged in various dilferent relations to one another. It will also be understood that in any instance of an engine of the present type employing more than two beater rolls, a duplicate or a substantial duplicateof the cover element heretofore described may be provided between each adjacent pair of the beater rolls. 11g

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the form, proportion and minor details of construction may be resorted to, without departing from the spirit of the invention and scope of the appended claims.

I claim:

1. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being transversely arched.

2. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively 13o beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being transversely and longitudinally 135 arched.

3. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a transversely and longitudinally arched top wall, and concave side walls merging into said top wall.

4. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating 'and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll. first acting on the stock is adapted to impinge, said cover element being inclusive of a top wall which is transversely arched substantially throughout its length and which merges into a horizontal straight edge disposed adjacent the beater roll next acting on the pulp stock.

5. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a top wall which is transversely arched substantially throughout its length beginning at a point closely adjacent to the delivery side of the roll first acting on the pulp stock.

6. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of top and side walls defining a pulp passage between said rolls, the top wall being transversely arched, and means serving to converge the sides of said passage adjacent to and toward the beater roll last acting on the pulp stock.

7. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a top wall which is longitudinally arched and which is transversely arched substantially throughout its length begin-' ning at a point near the delivery side of the roll first acting on the stock and merging into a horizontal straight edge near the feed side of the roll next acting on the stock.

8. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed acrosssaid channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of top and side walls, the top wall being longitudinally and transversely arched substantially throughout its length beginning at a point near the delivery side of the roll first acting on the stock and merging into a horizontal straight edge near the feed side of the roll next acting on the pulp stock, and the side walls merging gradually into the top wall.

9. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a top wall, and concave side Walls merging into said top wall.

10. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a top wall, and concave side walls merging into said top wall and converging relatively to each other in the direction of the roll last acting on the pulp.

11. A pulp beating engine comprising a receptacle having a pulp channel, a pair of beater rolls disposed across said channel for successively beating and circulating the pulp, the roll last acting on the stock being driven at a faster peripheral rate of speed than the roll first acting 1 on the stock, and a cover element between said rolls against which the pulp stock thrown upwardly by the roll first acting on the stock is adapted to impinge, said cover element being inclusive of a transversely and longitudinally arched top wall, and concave side walls merging into said top wall.

MELVIN A. MILLS. 

